The present invention relates to the planning and manufacturing of a weighing plant for dyes in powder form, operated with the help of a computer for the preparation of mixtures for dye works.
The preparation of mixtures to obtain a specific color, using basic colors is a standard procedure in the dyeing business and it represents one of the first phases of the dying process.
A known system for the preparation of the mixture consists in manually taking the basic dyes out of the containers which hold them and then weighing them.
The mixture which has thus been obtained, after having been dissolved and placed into another container, is sent to the production departments where it is put into the dyeing plants.
An inconvenience derived from said system of preparation of the mixtures is represented by the long period of time needed by the operator for the preparation of the mixtures themselves, since the operator is forced to perform several trips between the weighing station and the station where the drums containing the different dyes which need to be withdrawn are stocked.
Another inconvenience consists in the fact that it is extremely easy for the operator to make mistakes both in the dye he picks up and in reading the values of each weighing operation, which causes heavy economical damages, since it can happen that an entire stock of dyed material needs to be thrown away. It is obvious that this inconvenience leads to an inconsistency in the mixture and, as a consequence, to an inconsistency in the colors obtained with it.
Another inconvenience arising from the preparation of the mixture with the manual method is represented by the danger that, during the withdrawal and weighing procedures unwanted mixings or, at any rate, tainting of the stocked dyes may occur, due for instance to accidental transfer of dyes of one type into containers holding other types.
Not the least inconvenience is represented by the fact that the manual handling of dyes entails a dispersion of a certain quantity of dye into the air, which cause, at least in a small degree, the pollution of the working environment, with the ensuing damage to the health of the operators who are in charge of these procedures.
In order to avoid all the above listed inconveniences, plants consisting of rotating magazines with several stations have been planned and manufactured. On each station there is a drum containing a different type of basic dye. Said rotating stations are made to rotate by a mechanical control system operated by the operator, who chooses each time which container needs to be brought into the withdrawal position, according to the specific requirements of the mixture which needs to be prepared.
The withdrawal of the dye from its container and its transfer on the weighing scale are carried out by the operator himself who uses a scoop.
It is easy to understand how this system, although it does away with the need for the operator to move around to withdraw the dyes, does not eliminate the danger of tainting the dyes because of accidental transfer of the dyes from one container to the other. Above all, it does not eliminate in any way the pollution of the environment and, therefore, the hazards to the health of the operators.